1. Field of Invention
The present invention relates to a high efficiency electronic display device, especially to the like electronic paper display equipment made by electrophoretic display elements (EPD) and the adding cooperation for LED.
2. Description of Related Art
The electrophoretic display elements, called E-paper traditionally, are becoming more mature gradually in the field of electronic display equipment. The characteristics are low-rate of power consumption, thin thickness of 0.1 mm, display of self-maintain content, non-self-luminescence, etc.; wherein the low-rate of power consumption applying onto information display equipment may be a great advantage, and such equipment being operated based on battery without other power sources shall save a great cost of preparation. Thus the traditional LED display may be a disadvantage. In addition, the equipment for EPD having the features of lightweight and small size may be installed anywhere very easily, and this is superior than prior arts.
On the contrary, the main weakness of the equipment constructed by EPD is non-self-luminescence. Therefore at least one light source may be a necessity in a dark place or at night, and the low-rate of power consumption shall be lost. In the present situation, the sites for applying EPD are then restricted.
The inventor of the present invention has developed the technology related to the electronic display equipment for a long time and produced the device of the present invention. It is to combine the display equipment with EPD and LED; hence the device is able to display information by means of EPD in the daytime and LED light at night. The total amount of LED and related components of the device is 1/10 of the LED display traditionally used. Therefore the difference between the two devices is huge, because LEDs of the device of the present invention may be installed in the places where LEDs should be at night. Comparing with the EPD lighted by external light source, the present device is capable of saving 50-80% energy.
LEDs only light up the area where EPD display, other area without the LED need having contrast luminance comparing with the LED light may promote the light effect. As aforesaid, the high efficiency electronic display device only needs 1/10 of the amount of LEDs and related components of traditional LED display; further, the device weight of the present invention is totally different.
The present device is not suitable for display equipment with small size and more display points per square unit. Generally, display point being 10 mm may be acceptable, but other smaller display points may be involved in the present invention.
Please refer to FIG. 1, which is a side view of an EPD structure in prior arts. Two electrodes 102 and 103 on two sides of an electrophoretic material 101 connected to a voltage 104 are able to attract or repel charged particles with different colors, and a display unit is thus composed. FIG. 2 is a sketch for an EPD display in prior arts (slash areas represent dark pixels).